The present invention relates to a connecting device to a source of a liquid.
Specifically, though not exclusively, the invention can be usefully applied in connecting a medical apparatus, for example a dialysis apparatus, to a centralised supply plant of a medical liquid, for example a dialysis liquid.
As known, a centralised supply plant of liquid for dialysis is connected to a plurality of remote dialysis stations by means of a distribution circuit. One of the problems connected to this type of plant is protection against the risk of back-contamination of the whole distribution circuit due to a malfunctioning of a dialysis station in which, for example, a chemical disinfection process is under way: in this case, the propagation of the disinfectant in the distribution circuit would represent an enormous risk for the safety of the patients subject to treatment in the other dialysis stations.
US Patent Publication No. US 2005/0047959 describes a connecting device for connecting a medical apparatus (for example a dialysis machine or a inverse osmosis system) with a supply system of a cleaning or disinfecting agent. The connecting device comprises a buffer chamber or storage chamber, a connection line connecting the upper part of the buffer chamber with the medical apparatus, a siphon connecting the lower part of the buffer chamber with a source of the cleaning or disinfecting agent, and a vent line which connects the upper part of the buffer chamber with the external environment. The connecting line is provided with a pump for moving the cleaning or disinfecting agent and a closure valve. The buffer chamber is provided with a liquid sensor arranged at a level which is lower with respect to the top of the siphon and is superior with respect to the mouth of the siphon in the buffer chamber. The vent line is provided with a vent valve. During the washing and disinfecting procedure of the medical apparatus the closure valve is opened, the pump activated, while the vent valve is closed. During the other phases of the medical apparatus the closure valve is closed, the pump still, and the vent valve is open. The siphon ensures that at the end of the washing and disinfecting procedure, the buffer chamber is emptied of liquid. Further, the connecting device provides a security system which is able to detect if, beyond the procedure of washing and disinfecting, there are liquid leaks passing from the medical apparatus to the buffer chamber through the closure valve. The device serves to reduce the risk of contaminating the medical apparatus with the washing and disinfecting liquid when not in the stage of washing and disinfecting (for example during a medical treatment of a patient), as well as the risk of altering the washing and disinfecting liquid in a controlled way with medical fluid coming from the medical apparatus. In this way it is possible to keep the washing and disinfecting liquid constantly connected to the medical apparatus.
U.S. Pat. No. 5,015,389 describes a system for distribution of bicarbonate concentrate to a plurality of remote hemodialysis units, in which the bicarbonate concentrate is kept in continuous re-circulation along a ring-shaped distribution line, even in the presence of variations in the flow demand for the concentrate by the various hemodialysis units.
FR 2704150 discloses a plurality of dialysis machines connected to a central water purification unit by means of a supply ring which starts from the above-mentioned central unit and returns to the same unit. Each dialysis machine is provided with a connector for connecting the above-mentioned supply ring in order to ensure a continuous circulation of water along the ring and the taking of the necessary delivery of water for the functioning of the dialysis machine. Each connector is configured for connecting to a respective counter-connector which is predisposed along the supply ring. Each counter-connector is normally closed and is opened by effect of the mechanical interaction with a projection on the connector, predisposed on the dialysis machine. Each connector is provided with a solenoid to enable the water supplied to the supply ring to enter the dialysis circuit of the single dialysis machine.
DE 10047849 C1 describes a pure water distribution system, the water being prepared by an inverse osmosis plant, in which a ring-closed circuit supplies pure water to a plurality of dialysis machines. The same ring-closed circuit can be used to distribute the cleaning liquid to the various dialysis machines during the non-treatment stage (service stage) of the machines, in general during the night-time. Each dialysis machine is provided with a valve enabling ingress of the cleaning liquid coming from the distribution circuit. Further, the distribution circuit is provided with one or more temperature sensors connected to the control unit of each dialysis machine. The above-mentioned valve is opened by the control unit of the dialysis machine only when the temperature of the cleaning liquid, measured by the above-said sensor, has exceeded a predetermined suitable threshold.
EP 701827 describes a dialysis machine connected to a source of water via a control valve having two inlet ports, one for the water and another for the chemical disinfectant, and at least an outlet port which is connected to the intake of a pump and which is selectively placed in communication with one or the other of the inlet ports by means of a mobile obturator.
U.S. Pat. No. 5,256,371 describes a device for connecting a dialysis circuit of a dialysis machine to an external liquid source, in which the source normally comprises a water supply connection and a water discharge connection predisposed on the clinic's wall. The connecting device comprises an inlet line, an outlet line, a bypass line, and five valves arranged on the bypass line, two on the outlet line before and after the bypass line, and the other two on the inlet line before and after the bypass line. U.S. Pat. No. 5,256,371 further describes a method which uses the above-said connecting device for complete disinfection of both the dialysis machine and the above-mentioned connections fixed to the clinic's wall.
EP 622086 describes a connection of a dialysis machine to an external liquid source, the connection being provided with a safety device comprising two valves arranged in series along the connecting line, a pump for pressurising the intermediate tract of line comprised between the two valves, a pressure sensor operating between the two valves, and a control unit which performs a check on the integrity of the valves by monitoring the pressure in the intermediate tract of line.